KR20100072412A - Polymer nanotube using vapor deposition polymerization mediated electrospinning and their application as a adsorbent for heavy metal ions - Google Patents

Abstract

PURPOSE: A method for manufacturing polymer nanotubes is provided to facilitate the fabrication of the polymer nanotube which is effective for eliminating heavy metal ions by eliminating electrospinning nanofibers after introducing an effective polymer on the surface of the electrospinning nanofibers through vapor deposition polymerization. CONSTITUTION: A method for manufacturing polymer nanotubes which are effective for eliminating heavy metal ions comprises the following steps: manufacturing a polymer nanofiber using an electrospinning method; dipping a solution including metal salt into the polymer nanofiber; manufacturing a coaxial nanofiber by introducing a monomer effective for removing heavy metal ions on the surface of the nanofiber having metal salt; and eliminating the polymer nanoriber in the coaxial nanofiber. The polymer which is effective for eliminating the heavy metal ions is polypyrrole, polyaniline, polyimidazole, polythiophene, polyrhodanine, PEDOT, and poly(3,4-ethylenedioxythiophene).

Description

Polymer nanotube using vapor deposition polymerization mediated electrospinning and their application as a adsorbent for heavy metal ions

The present invention is to prepare a coaxial nanofiber by introducing a polymer monomer having a functional group effective to heavy metal ions by vapor deposition polymerization on the polymer nanofiber prepared by electrospinning (vapor deposition polymerization) And a method for producing a polymer nanotube made of a polymer that is effective for removing heavy metal ions by removing the polymer of the core portion, and the application to a heavy metal adsorbent, the uniformity of about 2-100 mn on the polymer nanofiber produced by electrospinning By introducing a polymer having an effective functional group to a heavy metal having a thickness to provide a method for producing a polymer membrane consisting of nanotubes made of the polymer to provide an adsorption membrane for heavy metal removal having a high heavy metal removal efficiency.

Nano-sized nanomaterials are one of the materials of recent interest due to their large surface area, the resulting improved properties, and phenomena (quantum effects) that are not seen in bulk materials. The use of micelle structures (micelles, etc.) is gaining attention as a method of producing such nanomaterials, but an expensive surfactant is required to make micelles, and a washing process must be performed several times during removal. There is a disadvantage, and it is very sensitive to experimental conditions such as temperature has a disadvantage in reproducibility.

Recently, the production of nanostructures using electrospinning is one of the active methods due to the advantages of being simple, inexpensive, and capable of producing continuous nanofibers. Moreover, the electrospinning method also has a process advantage that a nonwoven fabric polymer film can be obtained through one process. Therefore, it can be produced in the form of a film simultaneously with spinning, and the time taken for spinning is much shorter than the manufacturing method of other polymer nanostructures.

In recent years, as environmental pollution continues, the environmentally friendly methods (LOHAS) and environmental pollution prevention technologies have attracted attention, and technologies for adsorbing or detecting various environmental pollutants have been actively studied. In particular, heavy metal ions emitted from industrial wastewater, agricultural activities, industrial water, etc., pose a deadly danger to humans and ecosystems through various routes. Therefore, various adsorbents have been studied to remove heavy metal ions.

Fibers produced using the electrospinning method described above have a diameter of several micrometers to several nanometers depending on the production conditions, and the surface area per unit mass is very large and flexible, suggesting the possibility of adsorbent. The large volume of voids and the large dispersion of external stresses indicate the possibility of efficient adsorption membranes that have good flow rates and do not collapse structures when used as an adsorption membrane.

However, nanofibers produced by electrospinning have very low heavy metal removal efficiency despite having high surface area because no effective functional groups exist in heavy metals. Furthermore, in the case of polymers that are soluble in water such as polyvinyl alcohol and polyvinylpyrrolidone, which are representative of electrospinning, the adsorption of heavy metal ions in terms of poor chemical stability to aqueous solutions, considering that most heavy metal ions are present in the aqueous solution form Membrane applications are limited.

Therefore, manufacturing a polymer nanostructure with high surface area and effective functional groups for adsorption of heavy metal ions and excellent chemical stability to aqueous solution is useful as a filter system capable of efficient heavy metal ion removal and adsorption, toxicity and hazards of heavy metal ions, Considering recent environmentally friendly policies and researches, there is a strong demand.

An object of the present invention is to introduce a polymer having a functional group effective for the removal of heavy metal ions using vapor deposition polymerization on the surface of the nanofiber prepared by using an electrospinning method to solve the problems of the prior art, electrospinning The present invention provides a method for preparing a polymer nanotube made of a polymer that is effective for removing heavy metal ions by removing nanofibers.

In addition, another technical problem of the present invention is to provide a polymer nanotube having a high processability and excellent bust removal efficiency compared to the heavy metal adsorbent according to the prior art.

After numerous experiments and in-depth studies, the inventors have introduced coaxial polymers by using vapor deposition polymerization to remove heavy metal ions on the surface of polymer nanofibers produced by electrospinning, unlike conventional methods. After the nanofibers were prepared, experiments were conducted using a method of removing the polymers produced by electrospinning the core, thereby confirming that it is possible to prepare polymer nanotubes effective for removing heavy metal ions. The polymer membrane made of polymer nanotubes has been found to have significantly improved the efficiency of removing heavy metals compared to conventional adsorbents, and have led to the present invention.

Polypyrrole, polyaniline, polyimidazole, polythiophene, polyrhodanine effective for the removal of heavy metal ions using electrospinning-vapor deposition polymerization , To introduce a polymer (PEDOT, poly (3,4-ethylenedioxythiophene)) on the surface of the electrospun polymer, and then to remove the electrospun polymer to prepare a polymer nanotube.

Method for producing a polymer nanotube according to the present invention,

(A) preparing a polymer nanofibers by using an electrospinning method of a solvent in which the polymer is dissolved;

(B) supporting a solution containing a metal salt on the polymer nanofibers; And,

(C) preparing coaxial nanofibers composed of heterogeneous polymers by introducing a monomer of a polymer effective for removing heavy metal ions on the surface of the nanofibers into which the metal salt is introduced by using vapor deposition polymerization; And,

(D) by removing the portion of the polymer nanofibers prepared by electrospinning from the polymer coaxial nanofibers prepared above, it comprises a step of producing a polymer nanotubes effective for the removal of heavy metal ions.

The method for producing polymer nanotubes by electrospinning-vapor deposition polymerization according to the present invention is a completely new method that has not been reported so far. It is possible to produce nanotubes having a tubediameter. The thickness of the polymer could be easily adjusted according to the amount of the polymer monomer introduced during the vapor deposition polymerization. In addition, it can be easily manufactured into a membrane by using an electrospinning method, and has a process advantage in the manufacture of the adsorption membrane in terms of being manufactured by a simple process. Heavy metal removal efficiency performance of polymer membranes made of polymer nanotubes effective for the removal of heavy metal ions is not limited to the flow of the flow due to the high surface area and the microspace between polymer nanotubes. The polymer nanotubes produced can be used as adsorbents for next generation adsorption equipment used in facilities such as wastewater treatment plants or factories.

The kind of the polymer in the solvent in which the polymer is dissolved in step (A) is not particularly limited, and polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinyl acetate, which are soluble in water. And polymers such as polymethyl methacrylate, polyacrylonitrile, polystyrene, and polycarbonate, which are soluble in an organic solvent.

The electrospinning method refers to preparing polymer nanofibers by dissolving a commercial polymer in water or an organic solvent which is a solvent capable of dissolving a polymer, and electrospinning the polymer solution. The molecular weight of the commercial polymer used is preferably 9,000 to 1,000,000. (D. Li and Y. Xia, Adv. Mater., 16 , 1151, (2004))

In the electrospinning, the range of the applied voltage is not particularly limited. Preferably, the voltage is 1 to 60 kV. At a voltage lower than 1 kV, the polymer is not formed but a polymer is injected in the form of droplets. At higher voltages, polymer nanofibers produced due to high voltages are not continuous or irregular in shape.

The diameter of the polymer nanofibers produced through electrospinning ranges from 10 nanometers to several micrometers and can be controlled by variables such as solvent concentration, viscosity and magnitude of applied voltage. The amount of the polymer added in the polymer solvent is 1 to 30 parts by weight relative to the solvent for dissolving the polymer.

The metal salt used in step (B) is a metal salt that can serve as an initiator for polymerizing an effective polymer for the removal of heavy metal ions, and preferably serves as an oxidizing agent by an oxidation-reduction reaction. III) (FeCl ₃ ), iron (III) chloride hydrate (FeCl ₃ (H ₂ O) ₆ ), iron (III) sulfate (Fe ₂ (SO ₄ ) ₃ ), copper chloride (CuCl ₂ ), cerium sulfate (CeSO ₄ ), ammonium persulfate _{((NH 4) 2 S 2} O 8), sseryum amorphous titanium nitrate _{(Ce (NH 3) 2 (} NO 3) 6) is particularly preferred.

In the solution containing the metal salt, a solvent capable of dissolving the metal salt is preferably water or ethanol, and the concentration of the metal salt is preferably 1 to 50 parts by weight relative to the solvent, but may be higher or lower.

The time for supporting the metal salt is preferably 1 minute to 24 hours, but is not limited thereto, and may be shorter or longer than the above range depending on the concentration or type of metal salt.

The monomers of the polymer introduced by vapor deposition polymerization in step (C) are polypyrrole, polyaniline, polyimidazole having amine functional groups or thiol functional groups well known for the removal of heavy metal ions. Particular preference is given to monomers of (polyimidazole), polythiophene, polyrhodanine, pedot (PEDOT, poly (3,4-ethylenedioxythiophene)).

The amount of the monomer to be introduced is preferably 5 to 100 parts by weight relative to the electrospun polymer nanofibers, and the thickness of the polymer nanotubes that is effective for removing heavy metal ions is 2 to 2 depending on the amount of the monomer to be introduced. It can be adjusted within the range of 100 nanometers.

The temperature of the polymerization in the vapor deposition polymerization is preferably 150 degrees at room temperature, the polymerization time is preferably 1 minute to 24 hours, but is not limited thereto, and may be longer or shorter than the above range depending on the type of monomer.

In the step (D), the method of removing the polymer nanofiber part prepared by the electrospinning method preferably uses a solvent for dissolving the polymer, and water, acetone, dimethyl sulfoxide, and methylene chloride chloroform Chloroform is particularly preferred.

The temperature for removing the electrospun polymer portion of the core portion is preferably 150 degrees at room temperature, the melting time is preferably 1 to 24 hours, depending on the type of polymer may be long or short.

The present invention also relates to the application of the polymer nanotubes having a functional group effective for the removal of heavy metal ions prepared above to the adsorption membrane for heavy metal removal. The polymer nanotubes prepared by the method of the present invention have efficient functional groups for removing heavy metal ions on both the surface of the nanotube and the inner surface of the nanotube. In particular, the nanotube has a functional group on the inner surface of the tube as described above, the wall of the nanotube has a permeability (material) can enter the inside of the tube in the solvent or ions, and the structure of the electrospun nanofibers Since the polymer nanotubes were manufactured using the polymer nanotubes, the polymer nanotubes had a lot of fine pores compared to the polymer membranes or the bulk polymer membranes prepared by agglomeration of nanomaterials, and thus had a flow rate of excellent flow rate. In addition, these characteristics indicate that the above material can be used as a heavy metal ion adsorption membrane having a high heavy metal ion removal efficiency. However, the polymer nanotubes according to the present invention can be applied and applied to various anticipated applications without being limited to this exemplary use, and their use does not depart from the scope of the present invention.

EXAMPLE

Although specific examples of the present invention will be described with reference to the following Examples, the scope of the present invention is not limited thereto.

Example 1

Polymer nanofibers were prepared by electrospinning 10 ml of an aqueous solution of 0.6 g polyvinylalcohol with a molecular weight of 85,000 at a voltage of 15 kV. Scanning Electron Microscopy (SEM) was used to measure 100 nanometers. The polymer nanofibers were observed. (1) Then, 1 ml of ethanol, in which 0.1 g of iron chloride was dissolved in 0.1 g of iron chloride, was introduced into the polymer nanofibers for 1 hour, and then 0.6 g of pyrrole monomers were coaxially deposited through vapor phase polymerization at 50 degrees. And a 200 nanometer diameter coaxial cable in which polypyrrole with a thickness of 50 nanometers was introduced using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) (FIGS. 2 and 3). Polypyrrole nanotubes were prepared by removing polyvinyl alcohol, which is a core part of coaxial cable, at 70 degrees using excess water. Polypyrrole nanotubes having a diameter of 200 nanometers were observed through a transmission electron microscope (TEM). (Figure 4)

[Example 2]

Using the same method as in Example 1, 10 nanometer polymer nanofibers were prepared by electrospinning at 1 kV of 0.1 g of polyvinylpyrrolidone having a molecular weight of 9,000, and after introducing 0.1 g of pyrrole monomer, By removing the portions, polymer nanotubes that are efficient for the removal of heavy metal ions were prepared. (Diameter: 25 nanometers, tube wall thickness: about 7 nanometers)

Example 3

Using the same method as in Example 1, 10 micrometers of polymer nanofibers were prepared by electrospinning at 60 kV of 3 g of polyvinyl acetate having a molecular weight of 1,000,000, and 3 g of pyrrole monomers were introduced. By removing, the polymer nanotube which is efficient for the removal of heavy metal ion was produced. (Diameter: about 13 micrometers, tube wall thickness: 70 nanometers)

Example 4

Polymer nanofibers of 150 nanometers were prepared using polymethylmethacrylate using the same method as in Example 1, and iron chloride hydrate was introduced into the metal salt, followed by introduction of 0.6 g of pyrrole monomer, By removing the core portion using acetone, polymer nanotubes that are efficient for the removal of heavy metal ions were prepared. (Diameter: 220 nanometers, tube wall thickness: 35 nanometers)

Example 5

120 nanometer polymer nanofibers were prepared using polyacrylonitrile using the same method as in Example 1, and iron sulfate was introduced into the metal salt, and then 0.6 g of pyrrole monomer was introduced. By removing the core portion using dimethyl sulfoxide (dimethyl sulfoxide), an efficient polymer nanotube for removing heavy metal ions was prepared. (Diameter: 200 nanometers, tube wall thickness: 40 nanometers)

Example 6

120 nanometer polymer nanofibers were prepared using polystyrene using the same method as in Example 1, copper chloride was introduced into the metal salt, 0.6 g of pyrrole monomer was introduced, and an excess of methylene chloride was introduced. By removing the core portion using a), a polymer nanotube that is efficient for the removal of heavy metal ions was prepared. (Diameter: 190 nanometers, tube wall thickness: 35 nanometers)

Example 7

120 nanometer polymer nanofibers were prepared using polycarbonate using the same method as in Example 1, and cerium sulfate was introduced as a metal salt, followed by introduction of 0.6 g of pyrrole monomer, followed by an excess of chloroform. By removing the core portion using a), a polymer nanotube that is efficient for the removal of heavy metal ions was prepared. (Diameter: 180 nanometers, tube wall thickness: 30 nanometers)

Example 8

Polymer nanofibers were prepared using polyvinyl alcohol using the same method as in Example 1, after introducing ammonium persulfate as a metal salt, 0.6 g of pyrrole monomer, and then removing the core portion, Polymer nanotubes, which are efficient for the removal of, were prepared. (Diameter: 190 nanometers, tube wall thickness: 45 nanometers)

Example 9

Polymer nanofibers were prepared using polyvinyl alcohol using the same method as in Example 1, by introducing cerium ammonium nitrate as a metal salt, and then introducing 0.6 g of a pyrrole monomer, and then removing the core portion. Polymer nanotubes that are efficient for the removal of heavy metal ions were prepared. (Diameter: 210 nanometers, tube wall thickness: 55 nanometers)

Example 10

Polymer nanofibers were prepared using polyvinyl alcohol using the same method as in Example 1, and 0.03 g of aniline monomer was introduced to prepare a coaxial cable coated with 2 nanometers of aniline. Polymer nanotubes that are efficient for the removal of heavy metal ions were prepared. (Diameter: 105 nanometers, tube wall thickness: about 2 nanometers)

Example 11

Polymer nanofibers were prepared using polyvinyl alcohol using the same method as in Example 1, and a coaxial cable coated with 100 nanometer imidazole was prepared by introducing 1.2 g of a doped monomer, and the core portion was By removing, the polymer nanotube which is efficient for the removal of heavy metal ion was produced. (Diameter: 300 nanometers, tube wall thickness: about 100 nanometers)

Example 12

Polymer nanofibers were prepared by using polyvinyl alcohol using the same method as in Example 1, cerium ammonium nitrate was introduced into the metal salt, and imidazole monomer was introduced to prepare a coaxial cable, and the core part was removed. By doing so, polymer nanotubes, which are effective for removing heavy metal ions, were prepared. (Diameter: 190 nanometers, tube wall thickness: 45 nanometers)

Example 13

Polymer nanofibers were prepared by using polyvinyl alcohol using the same method as in Example 1, cerium ammonium nitrate was introduced into the metal salt, and then rhodanine monomer was introduced to prepare a coaxial cable. By doing so, polymer nanotubes, which are effective for removing heavy metal ions, were prepared. (Diameter: 180 nanometers, tube wall thickness: 40 nanometers)

Example 14

Polymer nanofibers were prepared by using polyvinyl alcohol using the same method as in Example 1, cerium ammonium nitrate was introduced as a metal salt, and then co-peptide was prepared by introducing ciophene monomer, and the core part was removed. By doing so, polymer nanotubes, which are effective for removing heavy metal ions, were prepared. (Diameter: 190 nanometers, tube wall thickness: 45 nanometers)

Example 15

The polypyrrole nanotubes prepared according to the method shown in Example 1 are configured as adsorption filters for the removal of heavy metal ions using a polymer membrane composed of polymer nanotubes as shown in FIG. 5. 20 ml of a 200 ppm mercury solution was flowed through the prepared polypyrrole nanotube polymer membrane filter, and when the mercury ions were detected through an inductively coupled plasma (ICP), 0.1 ppm of mercury ions were detected. The concentration was confirmed. A heavy metal ion solution below 0.2 ppm is an acceptable concentration of heavy metal ions prescribed by the Food and Drug Administration and changes from pink to green even in the presence of trace amounts of mercury ions to further confirm successful removal of mercury ions. , 10, 15, 20-tetraphenylporphinetetra sulfonic acid (TPPS), it was found that the filtered solution is pink, mercury ion was successfully removed through the polymer nanotube polymer membrane.

Example 16

When 20 ml of 20 ppm cadmium solution was flowed using the same method as in Example 15 using a fedot nanotube prepared according to the method described in Example 11, the cadmium concentration of the solution through the filter was 0.1 ppm. It was confirmed that it was.

Those skilled in the art to which the present invention pertains will be able to add various applications and modifications within the scope of the present invention based on the above contents.

1 is a scanning electron micrograph of the electrospun polyvinyl alcohol nanofibers prepared in Example 1 of the present invention;

2 is a scanning electron micrograph of the electrospun polyvinyl alcohol nanofibers / polypyrrole coaxial nanofibers prepared using the electrospinning-vapor deposition polymerization prepared in Example 1 of the present invention;

3 is a transmission electron micrograph of the electrospun polyvinyl alcohol nanofibers / polypyrrole coaxial nanofibers prepared using the electrospinning-vapor deposition polymerization prepared in Example 1 of the present invention;

4 is a transmission electron of polypyrrole nanotubes from which polyvinyl alcohol of electrospun polyvinyl alcohol nanofibers / polypyrrole coaxial nanofibers prepared using the electrospinning-vapor deposition polymerization method prepared in Example 1 of the present invention is Micrograph;

Figure 5 is a schematic diagram showing a filter for removing heavy metals using a polymer membrane using a polypyrrole nanotube prepared in Example 15 of the present invention.

Claims (8)

Preparing a polymer nanofiber using an electrospinning method of a solvent in which the polymer is dissolved; Supporting a solution containing a metal salt on the polymer nanofibers; And, Preparing coaxial nanofibers composed of heterogeneous polymers by introducing a monomer of a polymer effective for removing heavy metal ions onto the surface of the nanofibers into which the metal salt is introduced by using vapor deposition polymerization; And, Removing the portion of the polymer nanofibers prepared by electrospinning from the prepared polymer coaxial nanofibers, thereby preparing a polymer nanotube effective for removing heavy metal ions, wherein the polymer nanotubes are effective for removing heavy metal ions. Manufacturing method. The method of claim 1, wherein the polymer in the solvent is a polyvinyl alcohol, polyvinylpyrrolidone, polyvinylacetate, polymethyl methacrylate, polyacrylonitrile, polystyrene, polycarbonate A method for producing a polymer nanotube effective for removing heavy metal ions. The method of claim 1, wherein the molecular weight range of the polymer in the solvent in which the polymer is dissolved is 9,000 to 1,000,000. The method of claim 1, wherein the magnitude of the voltage applied by the electrospinning method is 1 to 60 kV. The method of claim 1, wherein the metal salt is iron chloride, ferric chloride, iron sulfate, copper chloride, cerium sulfate, ammonium persulfate, cerium ammonium nitrate. The method of claim 1, wherein the polymers effective for the removal of heavy metal ions introduced are polypyrrole, polyaniline, polyimidazole, polythiophene, polyrodinine, pedot, the preparation of polymer nanotubes effective for the removal of heavy metal ions. Way. The method of claim 1, wherein a thickness of the polymer effective for removing the introduced heavy metal ions is from 2 nanometers to 100 nanometers. The method of claim 1, wherein the solvent used when removing the polymer nanofiber portion is water, acetone, dimethyl sulfoxide, methylene chloride, or chloroform.

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